The invention relates to a writing, drawing, decorating or cosmetic pencil comprising a colour-delivering, polymer-bonded lead and a polymer-bonded wood substitute material, the wood substitute material at least partly covering or surrounding the lead along its length, there being disposed between the lead and the wood substitute material at least one adhesion promoter layer. The invention further relates to a method of producing a writing, drawing, decorating or cosmetic pencil of this type.
Pencils of the type mentioned above are known in principle. In this case, the wood substitute material replaces the naturally grown wood typically used to hold the colour-delivering lead.
Wood-mounted pencils in which the lead is surrounded or encased in natural wood have been known for some time. In recent years, the price of high-grade woods has risen due to their short supply and this has had a direct impact on the production cost of the pencils. In addition, comparatively large natural wood reserves are used in the production of pencils.
For this reason, people have strived for years to replace natural wood with wood substitute materials, which are more cost-effective and conserve natural wood stocks.
Hence, DE 42 30 792 C2 has already disclosed co-extruded pencils with a polymer-bonded lead and a shaft made from a wood substitute material in the form of an expanded polymer to encase the lead rather than wood. The disadvantage of such pencils, however, is that this sort of wood substitute material has a low modulus of elasticity and therefore a high elasticity, which the lead itself does not normally possess. The result is that the lead may break or be damaged in the pencil. In order to circumvent this problem, the lead is usually adjusted to the same elasticity, which in turn results in a significant deterioration in its writing properties.
It is furthermore to be seen as detrimental that a pencil with a wood substitute material made from an expanded polymer has a sharpening performance unlike that of naturally grown wood for the user. The customary sharpening noise and brittleness inherent in naturally grown wood are missing.
Furthermore, co-extruded pencils with polymer-bonded leads and polymer-bonded wood substitute material are known, wherein the wood substitute material has inorganic fillers. It must be seen as a disadvantage that the sharpenability of these pencils has to be classed as inadequate, on account of the inorganic fillers.